Apparatus for transmitting pictures



Jan. 11 1927.

'r. T. BAKER- APPARATUS FOR TRANSMITTING PICTURES 3 Sheets-Shoat 1 Filed Dec. 10 $925 Jan. 11 {1927.

T. T. BAKER APPARATUS FOR TRANSMITTING F YCTURES Filed Dec; 10, 1925 s Sheets-Sheet 2 J Q p l-U M 3 1% 1 J z :l in .i N a 4 i fifikfifihhuflhn lpllnulllllllllllll ,IIIIL llllllll IIMIIIL w A m -1111 N Jan. 11 1927.

T 'r. T. BAKER APPARATUS FOR TRANSMITTING PICTURES 75 Sheets-Sheet 5 Filed Dec. 10 1.925

,Patented Jan. 11, 1927.

UNITED STA ES PATENT OFFICE. I

THOMAS THOBNE BAKER, OF LONDON, ENGLAND, ASSIGNOR OI ONE-THIRD TO CHARL ES HENRY WATSON AND ONE-THIRD TO FREDERICK WILLIAM WATSON BAKER, BOTH OF LONDON, ENGLAND.

APPARATUS FOR TRANSMITTING PICTURES;

Application filed December 10, 1 925, Serial No. 74,589, and in Great Britain December 11, 1924.

This invention comprises improvements in and connected with the telegraphic transmission of pictures, diagrams and dther impressions, and is connected with methods and apparatusemploying synchronized drums at the transmitting and receiving stations, a feed in the direction of the axle of the drum being imparted to the transmitting orreceiving element, such as a stylus or illuminant, by means of a screw feed mecha nism.

' The principal object of vthis invention is to provide for the anti-frictional. mounting of the carriage and feeding by the screw, so that frictional losses or resistance may be minimized as much as possible.

The importance of the anti-frictional mounting of the carriage and feedin by the screw is that it is possible success ull to employ a small clockwork or ramop one type of motor for the driving 0 the drums, these motors possessing a suflicient power storage capacity for enabling the drums to be driven for a sufficient period of time for the transmission and receptionof pictures of reasonable dimensions, given that the said anti-frictional means are employed so that little power is absorbed by the feed. A further object of this'ir'ivention is to provide an efficient portable and compact construction containing within itself a spring motor, relay apparatus, a drum and carriage, and anti-frictional mounting and screw feed mechanism for such carriage.

According to this invention the transmitting-or, receiving element is supported by, a

I wheeled carriage running on rails and fitted with a knife edge disc or wheel engaging a fine worm or thread on the axle of the drum. The carriage may comprise a frame fitted with two wheels situated at a distance from one another and adapted for running upon one and the same track rail, these wheels giving two points of support and a third point of support bein at the point of contact between the knife edge and the feed screw which is parallel to the said track rail. The carriage is advantageously arranged to tip about the track rail for running it back or fdr putting it out of the way, a suitable guard being provided to prevent the wheels or rollers escaping from engagement with the rail when the carriage is tipped. The drum and carriage track rail are preferably mounted upon an elevated base or frame which is supported so as to permit of fixing the spring motor beneath it with the winding spindle extending vertically up through the base, The motor spindle is suitably geared, with the axle of the drum, and any necessary clutches are provided where required.

In this way a self-contained motor-driven apparatus is provided occupying very little space and capable. of being carried about with ease, this apparatus nevertheless being adapted for the reproduction of pictures of' reasonable dimensions which are telegraphi- 'cally transmitted according to the known princlpleof sending a succession of signals by theaid of a picture on a synchronous transmitting drum.

In order to enable the invention to be readily understood, reference is made to the accompanymg drawings illustrating one suitable construction by way of example, in

In the drawings, ais a plate or frame up- I on which is a bracket 6 and a combined bracket and housingc. Theparts b and a are fitted with bearin s for the axle of the drum d and the brac et 6 alsoserves for supporting a rail e, the opposite end of the latter being supported in a pillar f. The axle of the drum (1 comprises a plain part d and a part d threaded with a very fine pitch screw for the feeding of a carriage supporting the transmitting or receiving and recording element which, in the example illustrated is a stylus g. The carriage aforesaid comprises a bar It fitted with two grooved track wheels or rollers j disposed for running on one and the same track rail 6, and a trans verse armor part jk havin its free end bifurcated and fitted with earings for the axle of a knife edge disc I. As will be seen from Figure 1 the track wheels 9' are disposed'so that there is a relatively long wheel base on the track rail e, and the arm is is of such a len h that the knife edge disc Z en? gages the ne screw thread on the axle part 11 when the carriage is in the working position seen in Figure 1. The axles of the track wheels j may run in ball or roller bearings and the knife edge disc lmay be mounted to run between centres so as to reduce the friction toa minimum. Also, the knife edge disc I may be mounted with a slight inclination so that it runs nicely in the fine screw 'thread and has no tendency to mount the thread.

At the opposite end of the carriage to that at which the arm In is situated, there is fixedly mounted a transverse arm m fitted with a weight n. The stylus g is secured in a holder on a small lever 0 which is inans fluenced by a spring p. Thus, the weight n keeps the arm m down in a horizontal position and imposes an appropriate load on the knife edge disc Z to keep it in proper engagement with the feed screw d and the spring 10 keeps the stylus g lightly but firmly pressing down upon the drum 0?.

It will now be understood that if the drum d is revolved, the screw threaded axle part (I will operate the knife edge disc Z so as to feed the wheeled carriage along the track rail a and thereby carry the stylus 9 along the drum (1 from right to left of Figure 1. When the carriage is to be returned, or When for any reason, it is desired to have the stylus 9 out of the way the carriage is tilted about the rail 6 as fulcrum to the dotted line position in Figure 3, thereby removing the stylus g from the drum (Z and the knife edge disc 5 from the screw threaded axle part d At the rear of the carriage there is a projection g carrying a normal y horizontal pin 1* which takes just beneath the track rail 0 and prevents the grooved wheels j escaping from the track. A pillar s on the base plate a supports a horizontal guard 22 and it will be seen from the dotted line positions in Figure 3 that this guard t is engaged by the pin 1- when the carriage is tipped over the vertical dead centre, so that the weight is be 0nd the pivotal axis. Thus the carriage wi l remain in the dotted line position until it is turned down to the full line position when re uired for use.

n the plain part d of the axle there is fixed a pulley it which is driven through a belt 0 by the pulley 'w of the spring motor a: of the gramophone type. The motor a: is fixed beneath the base plate a so that its winding spindle 3 is vertical and extends upwards through the base plate, its upper end being thus accessible for application of a winding key. Beneath the base plate a there is also fixed the polarized relay device 3 of known type. The base plate a is supported upon pillars or standards 2 of a suitable height.

' This complete apparatus is readily inserted into or removed from the case seen in Figure 1, in which it is protected and is readily transportable with convenience and safety.

\Vhen the apparatus is to be used, the spring motor is wound up, and at the sending station a repared picture or diagram is placed arountlthe drum cl. At the receiving station a sheet of prepared paper is placed on the drum which is connected up as one pole in a local circuit which includes the stylus. At a given signal, the drums having been set in revolution, the sender and re ceiver lower the carriages of their respective machines so as to bring the knife edge wheels on to the feed screws and the transmitting stylus or device and the receiving stylus on to their respective drums. The sending station apparatus then transmits a varying line current which passes from stylus g to drum d through the paper, the latter carrying a preparation which is electrolyzed by the passage of the current. The electrolyzing of the preparation producesmarks of varying intensity which result in the com position of a picture in known manner.

It is essential to synchronize the drums at the sending and receiving stations, and for this purpose each is timed-to revolve approximately once in two seconds, for example. On the transmission drum axle there is a cam which, at each revolution makes a contact for sending a reverse line current for operatively affecting the polarized relay 3 of the receiving station apparatus. The latter, as shown on the drawing, comprises an arm 1 on the drum axle, which arm is arrested at each revolution by a stop 2 on an armature 3 of an electro-magnet 4 which is energized under control of the relay 3 The arm 1, in approaching the stop? presses back a spring catch 5. When the arm 1 is against the stop 2 which prevents further forward motion, the catch 5 springs out behind the arm 1 and prevents any rebound. However, the engagement of the arm 1 witlrthe spring catch 5 may also close a gap in the reverse current relay circuit so that the latter can be energized only when the arm 1 is in or approaching the stop position. The belt '1) slips on its pullcv when the drum is arrested, or suitable the tion clutches may be provided. For example the pulley umay be carried by asleeve7 slidably fitted upon the drum axle part d and pressed against a. collar 9 on such axle part by a spring 8 arranged between the pulley u and a collar 9 adjustably fixed on the spindle part. Thus, if the receiving drum be set to revolve at a'slightly quicker speed than the sending drum, it will be momentarily arrested at the completion of each revolution. Immediately after the arrest, however, the cam of the sending drum makes the aforesaid circuit contact so that the relay y is in fluenced by a reverse line current. Theresuch a nicety that it ishardly arrested at the completion of each revolution owing to the fact that the transmitting drum makes the release contact practically simultaneously with the arrival of the arm 1 at the stop 2 of the" receivinginstrument or instruments.

The feed screw d aforesaid, instead of being on an extension of the drum axle, may be on a separate spindle geared with the drum (1, if this arrangement is preferred for some constructions.

It is to be understood that although a re-- ceiving instrument with a stylus is ada ted for recording by having an electro ytic action on prepared paper 1n known manner, the carriage of the receiving element may support other r'ecordingdevices such as a v lamp having its rays directedor focused on to a spot on a sheet of sensitized paper wrapped around the drum. In this case the transmitting apparatus 'may comprise a light-sensitive cell acted upon by raysof light after passing through the image of the picture to be telegraphed. All such devices in transmittingor receiving apparatus may be generically referred to as telegraphic tracers, as they may be said to trace a line over the picture during the revolution of the drum and feed of the carriage.

It is further to be understood that although the machine of these improvements as eflicientlv as possible and that it should be. possible for the drum to make suiiicient revolutions under the drive of its spring motor for enablin the size of picture for which it has been designed to be reproduced by the power stored in one winding operation.

It may be advantageous to substitute worm gearing for the belt gear in which case the most convenient arrangement of the motor may necessitate the extension of the winding spindle throu h a side or end of the case. Also, insteado a friction clutch, it may be desirable-to substitute a positive clutch under automatic control, this clutch being opened at the moment of arrest and closed at the moment of release of the drum.

I claim 1. Apparatus for use in telegraphing pictures, diagrams, and the like, comprising a revoluble drum adapted for supportin a picture sheet, a wheeled carriage, a telegraphy tracer device supported on saidcarriage and adapted for extending over said drum, a carriage track parallel with the axis of said drum, afeed screw revoluble,with said drum, and a revoluble knife edge disc supported on said carriage and adapted for engaging said feed screw substantially as set forth.

2. Apparatus foruse in telegraphing picwheels one behind the other for tracking a single rail, a telegraphy tracer device sup'- ported on said carriage and adapted for extending over said drum, a feed screw revoluble with said drum, a single track rail parallel with the axis of said drum, and a revoluble knife edge disc supported on said carriage and adapted for engaging with said feed screw for feed of said carriage and also for forming with said wheels a triangulated support for said carriage substantially as set forth.

3. Apparatus for use in telegraphing pictures, diagrams, and the like comprising in combination a revoluble drum adapted for supporting a picture sheet, a wheeled carriage having its wheels arranged one behind the other for running on a single track rail, a telegraphy tracer device supported on said carriage and adapted for extending .over said drum, a single track rail parallel with the axis of said drum, said rail being adapted for serving as a fulcrum about which said carriage can be raised and lowcred 'so that its wheels act as a pivot bearing on said fulcrum, a feed screw revoluble with said drum, a.knife edge di'sc supported on said carriage and adapted for resting upon said feed screw and engaging the thread thereof, and a weighted arm on said carriage for appropriately adjusting the pressure of said disc on said screw substantially as set forth.

4. Apparatus for use in telegraphing pictures, diagrams, and the like comprising in combination, a revoluble drum adapted for supporting a picture sheet, a carriage fitted with single track grooved wheels, a telegraphy tracer 'device supported on said carriage and adapted for extending over said drum, a single track rail parallel with the axis of said drum and adapted for serving the track rail when said carriage is tilted about said track rail as fulcrum substantially as set forth.

5. In apparatus for use in telegraphing pictures, said apparatus being of the revolving drum type with carriage operated by feed screw revolving with said drum, 9. single track rail in parallelism with said drum, a carriage comprising a longitudinal member fitted with-aligned wheels for running on said track and two laterally extending members, one of the latter being fitted with anti-frictional means inoperative engagement with the feed screw and the other be; ing hingedly mounted and fitted with a loading weight and with a telegraphic tracer device, and self-contained motive power means in releasable driving engagement with said drum substantially as set forth.

6. In apparatus for use in telegraphing pictures, said apparatus being of the revoluble drum type with carriage operated by feed screw revolving with said dram, an

antifrictional. S pport and feed means'for;

said carriage comprising track wheels and a revoluble knife edge disc engaged with.

said screw by lowering said carriage about its track wheels as pivotbearings, and an adjustable loading on said carriage operative for maintaining. appropriate: feed engagement between said disc and screw substantially asset forth. f

7. In an apparatus of the character described, a rotary drum, a tracer device movably mounted in operative relation to the drum, aJsupportfor the tracer device, a; feed 7 screw'rotat'able with the drum, a rotatable I THOMAS THORNE AKER.

7,40 nally of the screw imparts movement to the a 

